<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>

  <body>
    <form action="" method="get">
      用户名：<input type="text" name="username" /><br />
      密码：<input type="password" name="password" /><br />
      <button id="btn">登录</button>
    </form>

  </body>
</html>
